Page 1 Chemistry 1A, Fall 2006 Final Exam, Version B Dec 12, 2006 (180 min, closed book) Name:___________________ SID:_____________________ GSI Name:________________ • There are 60 Multiple choice questions worth 4.34 points each.• There are 13 short answer questions.• For the multiple choice section, fill in the Scantron form AND circle your answeron the exam.• Put your final answers in the boxes provided. Answers outside the boxes may notbe considered in grading.• The homework and chemquizzes that each question is based upon is listed afterthe question e.g. [HW 1.13, CQ 7.3]Question Page Points ScoreQuestion 61 - 63 14 22 Question 64 - 67 15 28 Question 69 – 69 16 12 Question 70-72 17 12 Question 72 – 73 18 16 Total 90Page 2 1.) Which is a possible electronic configuration for O+? A) 1s22s22p4B) 1s22s22p23s1C) 1s22s22p63s1D) 1s22s22p5E) None of these2.) The following is a plot of electron kinetic energy vs. photon energy for the interaction of photons and oxygen atoms. What does point ‘I’ represent? A) electronegativity of OB) electron affinity of OC) ionization energy of OD) atomic radius of OE) photons emitted by O3.) In a one mole sample of carbon atoms, how many protons are in each nucleus? A) 5 B) 6 C) 7 D) 8 E) cannot be determined4.) In a one mole sample of carbon atoms, how many neutrons are in each nucleus? A) 5 B) 6 C) 7 D) 8 E) cannot be determined5.) What is the minimum energy (J) required to eject an electron from chromium metal? The work function for chromium metal is 7.00 × 10-19 J. [HW 1.14] A) 7.00 × 10-19B) 1.41 × 10-18C) 2.11 × 10-12D) 4.45 × 10-23E) 8.11 × 10-18I IIEkhvPage 3 6.) What wavelength radiation (nm) must be used to eject electrons from chromium metal with a velocity of 1.50 x 106 m/s? The work function for chromium metal is 7.00 × 10-19 J. [HW 1.14] A) 4.67B) 23.4C) 101D) 512E) 1157.) What energy (in Rydbergs) is required to excite an He+1 ion from its ground state to its first excited state? [HW 1.23, 1.25] A) 14B) 25C) 101D) 3E) 878.) How many electrons in an atom can have the quantum numbers n=5, l = 2? [HW 1.53] A) 1 B) 2 C) 6 D) 10 E) 329.) Which statement is true for many electron atoms? [HW 1.59, discussion] A) ‘s’ electrons shield more efficiently that ‘p’ electrons.B) The effective nuclear charge is independent of the number of electrons in an atom.C) Electrons with l = 2 are better at shielding than those with l = 1.D) Electrons may share the same set of quantum numbers for short times.E) Electrons cannot share orbitals.10.) Which neutral element would have the ground state electronic configuration [Ne]3s23p5? [HW 1.67] A) O B) Cl C) Ar D) P E) Al11.) What is the arrangement of the following atoms in order of decreasing atomic radius? Sulfur (S), Chlorine (Cl), Silicon (Si) [HW 1.82] A) S, Cl, SiB) Si, Cl, SC) Cl, S, SiD) E) S, Si, ClPage 4 12.) Which would be the mass spectrum of the products when acetylene (C2H2) is burned in oxygen? A) B) C) D) E) 13.) What is the formal charge on the oxygen atom in the ONF molecule? [HW 2.33, 2.43] A) -2 B) -1 C) 0 D) +1 E) +214.) What is the shape of the ONF molecule? [HW 2.33, 3.7] A) LinearB) BentC) Trigonal planarD) Trigonal pyramidE) Tetrahedral15.) Which intermolecular forces are important in liquid ONF? [HW 5.1] I: Dispersion / VanderWaals forces II: Dipole-dipole forces III: Hydrogen bonding A) I only B) II only C) III only D) I and II E) I, II and III16.) What is the I-I-I bond angle in I3-? [HW 3.9] A) 60 B) 90 C) 109 D) 120 E) 18017.) Which of the following is most paramagnetic? [HW 3.47] A) F2B) F2–C) F2+2D) F2+E) F2-218 44 18 44 18 44 18 44 18 44 π 2pπ*2pσ* 2sσ 2sσ*2pσ 2pPage 5 18.) What is the hybridization of sulfur in SF4? [HW 3.33] A) sp B) sp2C) sp3D) dsp3E) d2sp3Use the table of molecular orbitals for a diatomic molecule to answer questions 19 – 22 The arrow indicate the internuclear axis. 19.) Which antibonding orbital would form between atomic s orbitals? A) A B) B C) C D) D E) E20.) Which sigma bonding orbital would form between atomic p orbitals? A) A B) B C) C D) D E) E21.) Which is a π molecular bonding orbital? A) A B) B C) C D) D E) E22.) Which is the highest energy orbital? A) A B) B C) C D) D E) EFor questions 23 – 27, consider a mixture of four gases, Kr, He, Ne, and Ar in a closed 10 L container. There are 10 grams of each gas present. 23.) Which gas has the highest partial pressure? A) Kr B) Ne C) He D) Ar E) all are equal24.) Which particles have the highest rms velocity? A) Kr B) Ne C) He D) Ar E) all are equal25.) Which particles have the highest average kinetic energy? A) Kr B) Ne C) He D) Ar E) all are equalA B C D EPage 6 26.) If the partial pressure of He is 2.0 atm, what is the temperature of the system? A) 98KB) 270KC) 323KD) 440KE) 60K27.) If the temperature is doubled which is true of the energy of the system? A) The energy doubles.B) The energy increases by a factor of 21/2.C) The energy decreases by a factor of 2.D) The energy increases but the factor cannot be determined.E) The energy decreases but the factor cannot be determined.Continue with the next question: 28.) What is the change in internal energy of a gas undergoing the following process? A gas sample is heated in a cylinder by supplying 524 J of heat while a piston compresses the gas by doing 313 J of work. [HW 6.5] A) +211 JB) -211 JC) +837 JD) -837 JE) 0 J29.) Estimate the boiling point of dimethyl ether using Trouton’s rule which states that the entropy of vaporization of most liquids is about 90 J/K mol. The enthalpy of vaporization of dimethyl ether is 21.51 kJ/mol. [HW 7.16] A) 273KB) 425KC) 239KD) 310KE) 70K30.) Which of the following will result in a change in the solubility of AgCl for the reaction shown (assume Ksp for AgCl is ~10-8)? AgCl(s) ' Ag+(aq) + Cl-(aq) A) Addition of NaClB) Heating the reaction vesselC) Addition of AgClD) A & B but not CE) A, B, & CPage 7 For questions 31-36, consider the reaction C (s, graphite) ' C (s, diamond). Solid graphite is the standard state of carbon. ∆G°f for C (s, diamond) is +2.90 kJ/mol. The standard molar entropy for graphite is 5.70 J/K mol, and for diamond is 2.38 J/K mol. All values are for 298K. 31.) What is ∆G° (kJ/mol) for the reaction? A) +2.90 All answers were accepted on all versions due to the typo. B) -2.38A) +5.70B) +3.32C) -3.3232.) What is the equilibrium constant for the reaction